1. Technical Field
The present invention relates to an ink roller cover device of a portable type label printing applicator, especially an ink roller cover device of a portable type label printing applicator which device is capable of preventing dry-up of the ink roller.
2. Background Art
In the conventional portable type label printing applicators, an operation lever is operated on the label application device to activate the printing device. The ink roller applies ink to the printing device. Then printing is performed by the printing device stamping onto labels placed on the platen. They are notably used for example in retail stores to indicate the price and other information about the goods.
However, in such a portable type label printing applicator, when the ink roller is mounted on to the label application device in a stored or a standby state where it is not being used, the ink roller is constantly exposed to the air.
Accordingly, ink ingredients are impregnated into the ink rollers. Commonly used are inks that do not dry-up and that are penetration-drying types which when stamp-printed on labels, the ink infiltrates into the paper materials, such as fine quality papers for labels, and then this ink dries.
For fine quality papers for labels used indoor in retail shops, ink-penetrable materials are used together with the penetration-drying type ink. However, for labels applied on goods that are placed especially outside in do-it-yourself stores, weatherproof synthetic papers are used. Since the ink does not penetrate into these weatherproof papers, and the ink is hard to dry after being printed, ink prints may become illegible and may stain the goods if the ink roller is using the conventional penetration-drying type ink.
Accordingly, for ink rollers for outdoor use, the ink used is not a penetration-drying type ink but a quick-drying type. However, due to quick-drying of the ink, in the above described stored or standby states, the ink roller easily dries up, resulting in a problem of not being able to use it.
In addition, and not only limited to ink rollers for printing labels for indoor or outdoor use, the surface of the ink roller easily collects dirt and dust, and then attaches the dirt and dust to the printing characters of the printing device, thereby causing a problem of carelessly staining the stamped printing.
Reference is made to Patent Document 1: Japanese Examined Patent Application, Publication No. 1991-26663.